Pump



y 1965 E. T. BROOKS ETAL 3,185,101

PUMP

Filed March 6, 1965 INVENTORS. EUGENE T. BROOKS 8 JAMES A. LA MONICA United States Patent Eugene T. Brooks, Lisbon, and James A. La Monica, Salem, Ohio, assignors to Crane Company, New York, N.Y., a corporation of Iiiinois Filed Mar. 6, 1963, Ser. No. 263,206 2 Claims. (Ci. 193-111) This invention pertains to the art of fluid pumps and more particularly to an improved axial feed, centrifugal pump for pumping liquids such as water.

The invention will be discussed with particular reference to a pump having an impeller adapted to direct pressurized liquid radially outward through a diffuser to a pump outlet; however, it is to be appreciated that the invention has broader applications and may be used in other axial feed, centrifugal pumps.

The basic operation of a centrifugal liquid pump as de scribed above involves the initial creation of a vacuum that draws liquid into the pump, and then an arrangement for forcing the liquid under pressure from the pump. After standing idle, such a pump must be primed so that the impeller is substantially submerged within the liquid. By submerging the impeller, a partial vacuum is developed as the pump is centrifugally evacuated. For efficient operation, a substantial portion of this vacuum should be created adjacent the pump inlet so that maximum efficiency is attained in drawing liquid into the pump. Any atmospheric leak decreases the vacuum and correspondingly hinders the initial operation of the pump.

The present invention is directed toward a structural means for improving the priming feature of a centrifugally operated liquid pump by limiting, to a greater extent than heretofore possible, the ingress of air into the pump, resulting in better stability of the vacuum established by the rotating impeller. As a result, the pumping action of the centrifugal pump commences more quickly and more efiiciently. Further, the present invention improves, somewhat, the continuous operating characteristics of the pump.

In accordance with the present invention there is provided an improvement in an axial feed, centrifugal pump of the type comprising a casing having an impeller chamber and a shaft opening communicated with the chamber; an impeller in the chamber; a driving shaft extending through the opening and operably connected onto the impeller; a discharge means spaced radially of the impeller for accepting pressurized fluid from the impeller; and a packing means adjacent the opening and around the shaft for sealing the opening from the leakage of air. The improvement comprises spacing the impeller closely from the casing at the side of the impeller facing the opening to prevent substantial leakage of pressurized liquid between the casing and the impeller, a conduit means in the casing, the conduit means having an inlet radially outward of the impeller and in the discharge means for positively diverting a portion of the liquid from the impeller into the conduit means, and the conduit means having an outlet directed toward the packing means, the conduit means being formed integrally with the casing and comprising a channel opening toward the impeller and communicated with the outlet. By this arrangement, the packing is continuously subjected to a flow of liquid which tends to maintain the packing in a liquid envelope.

The primary object of the present invention is the provision of a centrifugal liquid pump having an improved primary means.

Another object of the present invention is the provision of a centrifugal liquid pump having an inexpensive means for maintaining a vacuum level in the pump during the priming stage which vacuum level was heretofore unobtainable without expensive structural elements.

Yet another object of the present invention is the proviison of a centrifugal liquid pump having a means for limiting the leakage of air between the impeller drive shaft and the pump casing.

Yet another object of the present invention is the provision of a centrifugal pump having a means for limiting the leakage of air through the packing between the impeller drive shaft and easing, which means maintains the packing substantially enveloped by liquid during rotation of the impeller.

Still another object of the present invention is the provision of a centrifugal liquid pump having means for maintaining the packing between the impeller drive shaft and the pump casing substantially enveloped by liquid during the operation of the impeller which means comprises a slot or channel in the casing for diverting a small amount of pressurized liquid from the rotating impeller toward the shaft packing.

These and other objects and advantages will become apparent from the following description used to illustrate the preferred embodiment of the invention as read in connection with the accompanying drawing in which:

FIGURE 1 is a side elevational view in section illustrating the preferred embodiment of the present invention; and

FIGURE 2 is a fragmentary view taken generally along line 22 of FEGURE 1.

Referring now to the drawings, wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for limiting same, FIG- URE 1 shows, a rotary or centrifugal pressure pump A of the type generally utilized for pumping a liquid such as water and driven by an appropriate means such as motor B through a suitable drive shaft 10.

In the drawings, the pump A is provided with an appropriate casing 12 having therein a chamber 14 containing the pump components, and chambers 16, 18 containing a jet pump. Further, in accordance with the preferred embodiment as illustrated, the pump casing is provided with a support head 2t? aflixed to pump casing 12 by appropriate means and adapted to support motor B in spaced relattionship with the pump component Within chamber 14 so that shaft 10 can drive the pump.

The pump A, as illustrated, is of the rotary of centrifugal type, and comprises an impeller 22 mounted within an impeller housing comprising flange 24 of support head 29 and diffuser 26 located within chamber 14. This housing is provided with one or more diffusion vanes or wall portions 28 leading through peripheral discharge passages 29 to the chamber 14. The diffuser 26 of the impeller housing forms a water-tight connection with mouth 36 of partition 31 which partition separates chamber 14 from chambers 16 and 18 so that fluid may be directed into the impeller as will be hereinafter explained in detail.

The impeller 22 is mounted on shaft iii, extending longitudinally through suitable packing means 32, which, in accordance with the illustrated embodiment of the present invention, comprises a packing 34, rotary seals 36 and 38, spring 40 and sleeve 42. This pacle'ng means 32 is utilized to prevent ingress or leakage of air into chamber 14, especially during the initial operating stage of the pump. Shaft 10 is drivingly connected by a suitable coupling 44 to the impeller 22 so that rotation of shaft 10 causes a corresponding rotation of the impeller.

To better understand the operation of pump A, other structural features of casing 12 are hereinafter described in detail. Within chamber 16 there is provided a jet tube 46 having adjacent one end thereof a nozzle 48 which is positioned within chamber 18. Directly opposite the nozzle 48 there is provided a pump inlet 50 and communicated with chamber 14 is a pump outlet 52. To provide communication between chamber 14- and jet tube 46, chamber 18 has an appropriately positioned jet opening 54 so that fluid can flow from chamber 14 through nozzle 48, tube 46, and mouth 30 into an axial intake 56 for impeller 22. Directly adjacent the end of tube 46 is a plug 58 which may be removed to prime the pump by filling chamber 14 with water that Will submerge impeller 22.

The operation of the pump as so far described is conventional. Rotation of shaft rotates impeller 22 in the direction of the arrow in FIGURE 2 so that liquid, such as water, entering inlet 50 passes through the tube 46 and into intake 56. From here, the liquid is centrifugally forced through discharge passages 29 into the chamber 14. Pressurized liquid within chamber 14 passes through jet opening 54 and nozzle 48 so that the intake of the pump can be boosted, as is commonly known in the art of water pumps.

During the initial operation of the pump, shaft 10 is rotated at a high speed which tends to sling, by centrifugal force, the liquid away from the surface of the shaft. This causes a liquid void adjacent the shaft that encourages ingress of air through the packing 32, thereby decreasing the vacuum created by rotating impeller 22.

In accordance with the preferred embodiment of the present invention, there is provided a fluid guide means 60 (see FIGURE 2) for diverting a small amount of pressurized liquid from the rotating impeller 22 toward the packing means 32 in concave recess 62. Guide means 60 comprises essentially, a channel or slot with a circumferentially extending scoop portion 66 extending in the opposite direction from which the impeller 22 usually rotates, and a radially extending portion 63 for directing liquid from portion 66 into the concave recess 62. The scoop portion 66 is preferably arcuate in shape and generally concentric with the impeller 22.

In operation, a small portion of liquid forced radially outward by impeller 22 is diverted by scoop 66- into Iadially extending portion 68. In this manner, pressurized fluid is forced or sprayed toward rotating shaft 10 which maintains the shaft 10 substantially enveloped within the liquid being pumped by impeller 22. This diversion of pressurized fluid toward shaft 10 offsets the tendency of the rotating shaft to sling liquid outwardly therefrom. Accordingly, packing means 32 is maintained in a moist condition which substantially increases the effectiveness of packing means 32 to limit unwanted ingress of air, espe-' cially during the initial operating stage of pump A.

It is appreciated that the invention has been described in connection with a structural embodiment; however, various structural changes may be made without departing from the intended spirit and scope of the present invention as defined in the appended claims.

Having thus described our invention, we claim:

1. In an axial feed, centrifugal pump comprising a casing having an impeller chamber and a shaft opening communicated with said chamber; an impeller in said chamher; a drive shaft extending through said opening and operably connected onto said impeller; a discharge means spaced radially from said impeller for accepting pressurized liquid from said impeller; and a packing means in said opening and around said shaft for sealing said opening, the improvement comprising: said impeller being closely spaced from said casing at the side of said impeller facing said opening to prevent substantial leakage of pressurized liquid between said casing and said impeller, a conduit means in said casing, said conduit means having an inlet radially outward of said impeller and in said discharge means for positively diverting a portion of liquid from said impeller into said conduit means, and said conduit means having an outlet directed toward said packing means, said conduit means being formed integrally with said casing and comprising a channel opening toward said impeller and communicated with said outlet.

2. The improvement as defined in claim 1 wherein said channel has a first portion extending in an arcuate path in a direction opposite to the direction of rotation of said impeller and a second portion extending toward said packing means, said first portion being said inlet and said second portion being said outlet.

References Cited by the Examiner UNITED STATES PATENTS 768,911 8/04 Schoene 103-111 1,889,397 11/32 Baumneckel 103-111 1,946,212 2/34 Jacobsen 103-11l 2,203,077 6/40 Carpenter 103-413 2,3 80,924 8/45 Carpenter 1031 13 2,402,995 7 46 Garroway 103--111 2,741,991 4/56 Disbrow 103-111 1 3,076,412 2/62 Harker et al 1031 11 FOREIGN PATENTS 708,593 7/41 Germany.

99,576 6/23 Switzerland.

JOSEPH H. BRANSON, JR, Primary Examiner. 

1. IN AN AXIAL FEED, CENTRIFUGAL PUMP COMPRISING A CASING HAVIONG AN IMPELLER CHAMBER AND A SHAFT OPENING COMMUNICATED WITH SAID CHAMBER; AN IMPELLER IN SAID CHAMBER, A DRIVE SHAFT EXTENDING THROUGH SAID OPENING AND OPERABLY CONNECTED ONTO SAID IMPELLER; A DISCHARGING MEANS SPACED RADIALLY FROM SAID IMPELLER; FOR ACCEPTING PRESSURIZED LIQUID FROM SAID IMPELLER; AND A PACKING MEANS IN SAID OPENING AND AROUND SAID SHAFT FOR SEALING SAID OPENING, THE IMPROVEMENT COMPRISING: SAID IMPELLER BEING CLOSELY SPACED FROM SAID CASING AT THE SIDE OF SAID IMPELLER FACING SAID OPENING TO PREVENT SUBSTANTIAL LEAKAGE OF PRESSURIZED LIQUID BETWEN SAID CASING AND SAID IMPELLER, A CONDUIT MEANS IN SAID CASING, SAID CONDUIT MEANS HAVING AN INLET RADIALLY OUTWARD OF SAID IMPELLER AND IN SAID DISCHARGE MEANS FOR POSITIVELY DIVERTING A PORTION OF LIQUID FROM SAID IMPELLER INTO SAID CONDUIT MEANS, AND SAID CONDUIT MEANS HAVING AN OUTLET DIRECTED TOWARD SAID PACKING MEANS SAID CONDUIT MEANS BEING FORMED INTEGRALLY WITH SAID CASING AND COMPRISING A CHANNEL OPENING TOWARD SAID IMPELLER AND COMMUNICATED WITH SAID OUTLET. 